Purchasing power parity for 15 COMESA and SADC countries: evidence based on panel SURADF tests

In this study, the panel Seemingly Unrelated Regressions Augmented Dickey-Fuller (SURADF) tests advanced by Breuer et al. (2001) are used to test the validity of Purchasing Power Parity (PPP) for 15 countries belonging to the Common Market for Eastern and Southern Africa (COMESA) and the Southern African Development Community (SADC) over the period of December 1994 to July 2008. The empirical results from the univariate unit root and panel-based unit root tests indicate that PPP does not hold for these 15 countries; however, Breuer et al.'s (2001) panel SURADF tests unequivocally indicate that PPP is valid for three of these 15 countries.